Today, the company claims, ”Japan has a custom of chicken for Christmas, and the origin of this custom is KFC.”

According to one Tokyo-based consumer, who gives her name as Chisato, this reasoning still holds sway. “Turkey here is hard to get, and we don’t have big ovens like in the United States, so it’s easier to eat fried chicken,” says Chisato.

Rie, an office worker, explains that her family’s trigger for eating KFC on Christmas is always TV advertising. When “the ad comes on, someone says, ‘Why don’t we eat a KFC bucket on Christmas,’ and somehow, we all feel that’s a good idea,’” she says.

KFC’s Holiday Bucket.

Japanese press declares 'Chicken War'

But in recent years, KFC’s Christmas supremacy has been in peril, as a new heavy-hitting contender has entered the ring: McDonald’s.

Dubbed a “chicken war” by the Japanese media, the battle of the bird has been heating up since 2010, when McDonald’s unveiled its fowl-centric "iCon" menu.

Popular business magazine Diamond reported it’s been “getting hotter and hotter in the chicken market,” especially since McD's CEO Eikoh Harada boldly proclaimed, “McDonald’s is No. 1 for chicken.”

An increasing emphasis on chicken

Although Harada admitted customers don’t yet think of McDonald’s as the leader in fast-food chicken, he pointed out that, with industry chicken sales at ¥392 billion and McDonalds’s with a 16.3 percent slice of the bird pie (¥64 billion), the Golden Arches actually holds top market share.

With the Yuletide season upon us, Kentucky is bound to track McDonald’s maneuvers, especially since KFC’s Naoyuki Oishi told the Japan Times, in a past interview, that the company’s average Christmas chicken sales represent 20 percent of annual revenue.

Still, McDonald’s denies any outright challenge to KFC, saying, “We are not trying to attack KFC. We are just focusing on chicken."